Method and apparatus for radius grinding



W. C. PALMER METHOD ANDVAPPARATUS FORv RADlUS GRINDING Filed Feb. 6, 1926 5 SheetSSheet 1 @TTOF/VEYJ Aug.2s, 1192s. y 1,682,412

v w. c. PALMER METHOD AND APIARA'JSl FOR RADIUS GRINDING Filed Fb. 6, 1926 5 Sheets--Sheet 2y Tis. 5. JZ'

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w. C. PALMER IETHOD AND APPARATUS- FOR RADIUQ GRINDING Filed Feb. e, 1925 5 sheets-sheet 3 Y AM [11E if 72 I 1 Y '11 :1] 1%!-1 4 l|11 1Q Z0 3:1 12a@ Q f if Y a 'l l 1f a ll lz l.

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w.y c. PALMER METHOD ANDAPPARATUS FOR RADIUS GRINDING v Filed Fab. s, 192e 5 sheets-sheet 4 Aug. 2s, 192s.

A 1,682,412. v w. c. PALMER v IETHOD AND APPARATUS FOR RADIUS GRINDING med Feb.s, 1926 5 sheets-sheet Hw- @ffy 1 wiz/fm a. Eby@ i im wf )maal .long radii.

Patented Aug; 28, 192.8.

" UNITED sTATEs PATENT ori-ica vWILIiIaiiI c.. Plummer DAVENPORT; Iowa, assIeNora To MICRO macimm conr- EANY, orc-Burfrnunonr, Iowa, A conromrIoN or, IOWA.

EET-EOD APPARATUS FOB. RADIUS GRINDDQ'G.

applicati@ nica February s, 192e. semi in. 86,412.

This 'invention relates to grindinginachines andy to means -for grinding true. circular arcs. It more particularly relates to a relatively small and compact unit for use with a standard grinding machine to make possible the grinding of true circular arcs of It is frequently desired, particularly in railroad work, to grind true circular arcs of long radii, for example, in the grinding of locomotive radius links, and link yblocks for movement within such links. For economy in space and in investment in machinery a radius link grinding unit which may be used Witha standard grinding machine is very desirabl e. It is furthermore 'desirable that such a unit be provided with a self-contained acwheel employed. f

large and cumbersome equipmenttherefor.

It may be mentioned that it is very desirable that radius links and blocks should'l be formed with bearing surfaces of true circular arcs in order to provide the most efficient operation and longevity of the locomotive mechanism.

An object of my invention is to provide a relatively small, compact mechanism for l shown in Fig. l;

grinding true circular arcsof long radii.

Another object of the' invention is to provide a` compact mechanism for use with a standard grinding machine for grinding arcuate surfaces.

A further object of this invention is to provide a compact radius linkgrnding unit foruse with a grinding .'machine, said unitattachment having its own powermechanism formoving the work in-an arcuate path wit `^respect to the grinding wheel.

Another object of my invention is topravide a radius link grinding unit for Vgrinding machines, said unit having means thereon for. making accurate. settings of lo1g radii, andl for compensating' for the 4size of grinding A further object of ni'yinvention is topro- .vide a mechanism for true circular arcuate surfaces, saidV mechanism having a large adjustable' Worli' support whereby a plurality of-exactly duplicate concentric arcuate surfacesmay be readily ground.

'Another obJect of the invention' is to provide a radius grinding unit for a grinding machine, said unit having means to move the work transversely o f the grinding wheel spindle and means for automatically reversing said transverse motion.

A further object. of this invention is to provide a compactr-mechanism for grinding true circular, arcuate surfaces in which the theoretical center ofthe arc isiloating or movable.

Another obje-ct of the invention is to provide a compact means for grinding true circular arcuate surfaces in which the entire work support except the axis of pivotal movement thereof moves in a true circular are about a moving theoretical center, the said axis of 'pivotal movement moving 'in a straight line.

Other objects of this invention will be apparent to those skilled in the art from the description of it hereinafter given.

In the drawings:

Figure l is a plan view of a. radius grinding Vunit embodying'my invention, a radius link to be ground being shown partly in secunit;

Fig. 2 is a rear elevation of the mechanism tion, and the grinding Wheel and spindle be' Fig. 3 is an enlarged sectional view of the i gear case taken on the brokenline 3 3 of Fig. f1;

Fig. 4 is a vertical section von line 4.--4 of Fig. 3;

Fig. 5 is an enlarged fragmentary lbottom plan view of the means for reversing the travel of the sliding carriage;

Fig.'6 is a vertical section on line 6-6 of Fig. 7 Vis a vertical section on line 7-7 of j Fig,V S is an end elevation of the radius grinding unit showing the gear case in the foreground and the Vwork supportingmeans at 'the left; Y

radius graduations thereof and showing a pivoot stud with a cooperating member providico Yof the of the work 6 ongitudinally of the grinding ed with aduations for correcting for the size of grmdin wheelL;

Fig. 10 is a diagrammatic view illustrating the operation of the grinding unit;

Fig. 11 is a diagrammatic view similarto that shown in Fig. 10 showing the unit in a second position" and Fig. 12 is a diagrammatic view similar to that shown in Fig. 11, showing the' unit in a third position.

I have shown in the drawin a mechanism adapted to be employed with a standard grinding machine. It will be understood, however, that mechanism embodying my in-V vention may be embodied in an integral radius grinding machine.

My device is-shown as comprising the base 1 which may be suitably secured to the reciprocable table of a standard grinding machine, such, for example, as shown in the reissued U. S. Letters Patent No. 16,043 to Joseph. In such a grinding machine, the table is preferably reciprocable` longitudinally of the axis of the grinding wheel thereof. lOn the hasel 1 is mounted the slidable carriage 2, which, in turn, carries the hollow sleeve 67 in a trunnon` bearing 4. Angular control plate 3 is di osed in fixed relation to the sleeve 67. Ad1ustably secured to and vertically movable with respect to the control plate 3 is the work support or mounting plate 5. Pivotal movement is transmitted to the work 6 mounted on the support 5 from the angular control lever 7 which is pivotally connected to the hollow sleeve 67, as will be more fully described hereinafter. In other words, the lever 7 is pivoted at the pivotal axis of the work support 5. The power for moving the carriage 2 transversely ofthe grinding wheel spindle 8 is obtained from the motor 9 and transmitted through ears in the gearcase 10 to the screw 11 which drives the carriage 2. A The work mounting plate 5 is given ivotal movement abdut the axis of the ho ow sleeve 67 and trunnionobea .4 throu h the pivotal movement of the angu ar contro lever circular arc of the desired radius. Thus, the

pivotal axis of the work support 5 will travel in al lane ,which includes theaxis of the grindm `wheel 12, or, in other words, the

axis of t e ding wheel 12 lies in the plane oftavel Q the pivotal axis of the work support 5.

It maybe noted that the carriage 2 and the work 6 are shown as movable transversely wheel spindle 8. Movement wheel'spindle may-be obtained by moving the i Il l grinding grinding machine table-on which the radius unit is mounted. or by moving the' grinding wheel spindle relative to. the unit.

veraing the With the mechanism as shown, the carriage 2 may be moved longitudinally of the base 1 I in either direction and at either of two speeds. Mechanism is also provided for automatilly reversin lthe direction of lon 'tudinal A ovement of t e said carriage 2. e motor 9 whicli'is mounted on a motor pad 13 transmits power to the drive gear 14 by gear 15 mounted on the shaft of the motor 9. The said drive gear 14 is mountedon shaft 16.

-In the gear case 10 the shaft 16 is provided with keyed gears 17 and 18. Intermediate shaft 19 is provided with keyed gears 2O and 21 and floating gears 22 and 23. Clutch collar 24 is adapted to engage with detente in either gears 22 or 23. The said clutch collar 24which is keyed to shaft 19, is 'actuated by means of the clutch arms 25. Drive screw' shaft 11 is provided with floating gears 26 and 27 and a clutch collar 28 longitudinally `actuated by clutch arms 29. Clutch 24 is ada ted to change the direction of rotation of rive screw 11 and clutch 28 is adapted to rotate said screw 11 at high or low speed.

Referring to Figs. 3 and 4, when the clutch 24 ,is in the position shown in Fig. 3 and the l clutch 28 is engaged with the gear 27, the powerV will be .transmitted from shaft 16 through gears 17, 23, 21 and 27 to shaft 11, which will be caused to rotate' in the same direction as the shaft 16, and at high speed. With the clutch 28 engaging the gear 26 and the clutch 24 engaging the gear 23, the power will be transmitted from"shaft 16 through ars 17, 23, 20 and 26 to the shaft 1l, wherey the shaft 1l is caused to rotate in the same direction as shaft 16but at low speed. When the clutch 24 engages with gear 22 the power site to that of the shaft 16, and shaft 11 may be rotated at high or low speed as previously mentioned, dependin on the position of the clutch 28. The ,clutc 28 is operated by hand 1 by means of lever 31, as will readily be seen by referenceto Figs. 3 andi-4. Clutch 24 is lolperated automatically or by hand throu h t e mediumof lever 3211s will be more explained hereinafter.

By means of drive screw ,1 1, therefore, the A carriage 2 may be caused to move longitudi nally'of the base 1 in either direction and at high or low speed. The'end 11'l of the shaft 11 is suiabiy Shaped so uur Yau. Siae 11 may be rotated by a hand crank if diired. In the transverse movement of the carria 2bt1hesurfaces33and34of`the carriagesli l y engage 'of thehase 1.

lMeans is provided for automatically re- 'on of movement of the carriage 2 longitudinall' y of the base 1 after apredetermined ength of travel. Thus the shaft i8 Slidably supported with the corresponding surfaces is attached to the carriage and is adapt- 'ed to engage the adjustable collars 37 for reversing the direction of travel of the carriage, the collars 37 being spaced according to the travel of the carriage desired. Re-

ferring particularly to Fig. 5, slidably secured to ,the Ashaft is a link 38 which is fixedly secured to the tripping plunger 39. A pin extends transversely of the plunger 39 through aperture 41 in the lever 32, the pin 40 being adapted to move the lever 32 to thereby throw the clutch 24. Surrounding the shaft 35 on both sides of the link 38 are the compressible springsv 4,2 and 43 which are fixed against translation along the shaft 35 by the adjustable collars 44 and 45. Also disposed on the shaft 35-are the stop pins 46 and 47. Mounted on the pin's 48 and 49, which are affixed to' the lower portion of the base 1, are pawls having the pawl arms and 51, and52 and 53, respectively. The arms 51- `and 53 are ordinarily disposed between the pins 46 and 47 on the shaft 35. I'he arms 50 and' 52 are adapted to engage inu notches 54 and 55 in the tripping plunger 39. The distance between the grooves 54 and 55 is preferably less than the distance between the outer edges of the arms 50 and 52 when the said arms are in' substantially aligned relation. The arms 50 and 52 are maintained in contactwith the plunger 39 by'afspring 56 disposed between the arms 51 and 53. The operation of the automatic reversing mechanism is as follows: Referring to Figs. 2 and 5, assume the arms 50 and 52 to be in the position as shown and that the carriage is traveling to the right. The arm 36 will engage the collar 37 and cause the shaft 35 to move to the right.

This will compress spring 42 and bring the pin 46 adjacent to the' pawl arm 51. When the shaft 35 has moved far enough to the right the pin 46 will engage the arm 51 and release the arm 5() from engagement with the plunger 39. On such release of the arm 50,

the plunger 39 will be forced'to-the right due tothe force imparted thereto by the release of the compressed spring 42. The movement of the plunger 39 will shift the clutch 24 through the medium of pin 40, lever v32, shaft 57 and clutch arms 25. When the plunger 39 is shifted, the awl arm 52 will engage in`y the groove 55 an the reverse procedure will take placev when the carriage 2 has come to the extreme left of'its travel. A handle 58 is provided at the end of the shaft 35 so that the direction of travel of the carriage 2 may be reversed by hand whenv desired.

The pivotal movement of-the work supporting means 5 and work 6 is dependent on and. proportionate to the longitudinal travel ,of the carriage2. Referring partlcularly to. F igs.'2.and 7, attached to the base 1 1s a rack` 59 which engages with the pinions GO- and causes to rotate. when the 'carriage 1s m motion. Mounted on the carriage and in locked relationwith the pinions 60 are the angular control screws 6l. Cooperatingwith the screws 61 and movable vertically thereby is an angular control channel member 62 to which is attachedV a member 63 moving vertically in cooperative relation with a suitable slide 64. The lever arm 7 is thus movable about its pivotal axis by member 62 movable longitudinally in a plane perpendicular to the plane of travel of the pivotal axis of the work support 5. The channel member 62 is provided on one side thereof with a groove or channel 6.2a in which an adjustable pivot stud 65 is slidable. The stud 65 is adjustable in the slot 66 in the arm 7 which is graduated according to the desired radius of .curvature of the surface to be ground. It will be noted that the said graduations are uniform andcxtend substantially throughout the length of the lever arm 7, and that therefore the scale of said graduations is relatively large, thus making it readily possible to obtainaccurate settings of the stud 65.- The stud 65 is set in fixed relation to the lever arm 7 at the desired radius, thereby determining the eective length of the leverl arm 7. Associated with the pivot stud 65 is a member 73 graduated in such 4manner that allowance for the diameter of a grinding wheel 1-2 may be made in setting the stud 65 without the v necessity for calculation. The member 73 will be further described hereinafter. Thus, a pivotal movement is imparted to the angular control lever which in turn imparts'a pivotal or angular motion to the hollow sleeve 67 and thereby to the Work support 5 and the work 6. Pivotal motion of the support 5, therefore takes place in proportion tothe longitudinal movement of the carriage 2. It will be noted that the pivotal movement of the work support is reversed simultaneously with the reverse of longitudinal travel of the carriage 2. Furthermore vthe-radius of the resultant arcuate movement of the work support is dependentmn the eiiective length of the lever arm 7 as determined by the position of the pivot stud 65. In this connection, the pivot stud 65 may be considered to define the outer .effective end of the lever arm 7.

In my machine I have provided for arelatively. great vertical adjustment of the work support 5 so that with one clamping of the work a plurality of concentric or duplicate surfaces may be ground accurately. By this Vmeans re-clampingof the work for two .or

more indin s is unnecessary and hence no errors can arise therefrom. Thus I have provided a relatively long svcre'w68V mounted in suitable bearings and cooperativelyassociated .with the threaded block 68* which is ri 'dly attached to the Workgsupport 5. 'Attac ed diameter of the grinding wheel is'2 in pivot stud 65 at the proper diameter,

rovide the stud 65 with a graduated memberwith the bevel gear 70 which, in turn, is affixed to the shaft 71 mounted in suitable bearings within the' hollow sleeve 67. The shaft 71 may be rotated by hand by means of a crank disposed on the suitably shaped end 72, and the work support 5 thereby moved longitudinally with respectn to the screw 68. Thus, if a plurality of concentric or duplicate arcuate surfaces are to be ground, the one or more pieces of work 6 may be clamped on the work support 5 and concentric or exactly duplicate arcuate surfaces ground consecutively merelv by longitudinal adjust ment of the work support with respect to the screw 68 to bring the particular surface to be ground in cooperative relation with the grinding wheel 12. The advantage of this feature will be readily appreciated when it is noted that thereby a link block and its corresponding link may be simultaneously clamped to the work support and all the cooperating arcuate surfaces ground to exactly the desired curvature.

In the present apparatus the diameter of the grinding wheel 12 is compensated for by suitably setting the stud 65 with respect to the graduations on the lever arm 7 rllius, as inl grinding an external arc, if the grinding wheel is disposed above the surface to be ground, as indicated in Fig. 6, and if, for example, the diameter of the grinding wheel is two inches and the desired radius of the ground surface is 40 inches, the stud 65 would be set at a radius equal to the radius desired plus one-halfV the diameter of the grinding wheel, which in this case would be 40 plus l, or 41 inches. If with the same dimensions as given the grinding wheel is disposed below the surface to be ground, as in grinding an internal' arc, the setting will be made at the desired radius minus one-half the diameter of the grinding wheel. The above corrections are made due to the fact that the grad-l uations on the angular control arm 7 refer tothe center line o the grinding wheel and -the grinding wheel spindle, so' that said graduations may be universally applicable regardless of the size of grinding wheel used.

To Y more readily make allowance for the diameter of the grinding wheel in setting the I may 3, whereby such corrections may be made without calculation. The graduations of the member 73 'may be read in terms of grinding wheel diameter in each direction from a cen tral point, zero; thus, for example, if the grinding wheel is dis osed above the surface to be ground in grin ing an external arc, as indicated in Fig. 6, and if'for exam le tli an the desired radius of the ground surface is 40 inches, the point 2 to the left of-.tbe z ero on the graduated member 73 is disposed directly opposite the point 40 on the lever 7. If the grinding wheel were to be disposed below the surface to be ground as in indin an internal arc, the oint.2 to the right of t e zero on the member 73 would be disposed opposite the point 40 on the lever 7.

In operation, the grinding wheel spindle 8 is, in one position of the carriage, in direct alignment with the center of the trunnion bearing 4, which center may be represented by the axis of the shaft .71. When the carriage is in longitudinal motion the axis of the shaft 71 and the point on the w'ork support directly opposite said axis move in a straight line. Thus itmay be said that during the operation of the mechanism, one and only one point on the work suppoit moves in a straight line. Furthermore, the Work supporting table 5 and the work 6 describe a true circular arc about a theoretical center which is floating or movable in a circular path with the axis of the grinding wheel as a center` The circular arc motion given to thework t is the result of-the combination of the transverse movement 0f the carriage 2 and the pivotal movement of the angular control plate 34 It may be noted that the pivotal axis of the work support 5 as represented by the axis oi shaft 71 remains in fixed lateral position rela tive to said work support 5 during the operation of the grinding machine.

The operation of my improved grinding unit and the fact that a true circular are if to'be ound will be more readily un'derstoocl by re erence to Figs. 10, 11 and 12, in whicl 'three positions of a unit are diagiammatical ly represented. In Fig. 10, E represents thl pivotalnaxis ofthe work support 5 which in thl drawings is in alignment with the axis of th shaft 71 and hollow sleeve 67.

rIghe line AB represents thev path along which 'the point E moves during the operatioi of. the grinding unit. The center of thi grinding wheel is shown in alignment witl the center of lpivotal movement of the worl support 5 anl therefore coincides with th point E. S represents the position of thi pivot stud 65 which in Fig. 10 is disposed o1 the line AB, the length of the angular contro lever being represented by the distance ES The work 6 to be ground is shown in co-oper ative relation to the grinding wheel, F bein, the point of tangency between the grindinI wheel 12 and the work 6. The theoretica center of the arc HK to be ground is shown il Fig. 10 at G, FG being the radius of tbe ar to be ground. Arc MN is concentric wit HK, the true circular arc to be ground, an passes through the axis of the grinding whee G is shown in Fig. 10 as being'disposed on tb vertical center line TU of theIgi-indingwhei and also on the circular arc C whose oente is at E; it can be mathematically shown tha the path of the theoretical center of the :rot be ground is along circular are CD, whos center is at E-and whose radius is equal to th distance EG. In Figs. 10, 11 and 12, ES is shown as equal to GE.

In Fig. 11 the carriage 2 is shown as havlng traversed a horizontal distance equal to EE', the pivotal axis of said carriage assuming the new position E. The point S of Fig. 10 1s shown as having traversed a vertical distance RS to assume new position S. The length ofthe angular control lever is therefore indicated by the distance'ES. The theoretical center of the arc to be ground has moved to the point G on the arc CD. The arc MN is tangent to the line ES atE'.- The arc EE and the chord EE are therefore included between the radii EG and G-E. The line PG is a lbisector of the chord EE. Mathematically, angle EGP is equal to the angle PGE is equal to the angle RE'S.

Since the triangle GPE and ERS are similar, as can be mathematically proved, and in the` present case equal, the ratio of VT, the vertical travel of the pivot stud 65, represented by RS in Fig. l-1,to L, the effective length of the lever arm 7, represented by ES in Fig. 11, is equal to the ratio of onehalf HT, the horizontal travel of the trunnion center, represented by EE in Fig. 11, to R, represented by the radius GE, and, by transposition,

RVT

. Figs. 10, l1 and 12 the expression I VT p is equal to-1 Whereas inthe shown in Figs. l to 9 inclusive this ratio is shown as equaling 4 in order to make the lever arm relatively short and to permit of the construction of a relatively compact machine. This ratio,A however, can be made of any suitable value according to the size of complete unit1 desired, In the drawings it can also be mathematically proved that VT, the vertical travel of the pivot stud 65, is proportional to the sine of the angle PGE.

f This relation is true whatever the value of the ratio .VT may be taken to be. In operation, therefore,-

at successive positions of the pivot stud 65,

the vertical travel of the said stud and of the portion of vvthe leverarm 7 cooperating therewith, will be proportional to the sine of half the angle included between the` theoretical center of the arc'being ground and the pivotal axis of4 the work support 6. at corressponding successive positions thereof. If

the amount of-horizontal travel of the carriage 2, namely HT, bedoubledthe value of the sine of the angle PGEalso becomes doubled, but the number of degrees of said` .asofalink this reason, if the angular movement of the work support were to be obtained by gears,

a true circular arc could never be ground, be-

cause the work support when moved angularly by gears must move in proportion to the increase in the number of degrees in the above-mentioned angle and not in to the change in the sine thereof.

Moreover, with angular rotation by gear-` ing, as the length of are' being ground .is increased, the variation of said arc from a circular shape is increased, since there is an increasingly greater variation between the sine of the above-mentioned angle and the value of the angle.

In my grinding mechanism, since the ratio of HT, the horizontal travelof the carriage, to VT, the vertical travel of the pivot stud is held constant during a grinding operation, the formula for R, the radius from the theoretical center of the .are being ground to the axis of the grinding wheel, may be 'applied at any point of the travel, such' as third position of the carriage and pivot"stud shown in Fig. 12 where the horizontal travelof the carriage is ,represented by the distance E and where the vertical travel of the pivot stud is represented by RS, the theoretical centeil of the arc being ground being shown at It willbe noted that short and compact mechanism for grinding true arcs of longradii,

which'mechanism is 4adapted lto be employed with a standard grinding machine.

It will 'be :further noted that since my irn-4 proved grinding machine unit has its own,

mechanism.

It will thus be seen that I have provided a method whereby the opposed sides of a link,-

link block or similar articlel may be'ground concentrically to arcs of true circular shape, and whereby corresponding arcuate surfaces, and link block, may be ground to the proper curvature.

proportion I have provided a.

provided a grinding f lunit having its own automatic reversing It will alsobbeseenthat I have provided a I work support having a relatively great working adjustment so that a plurality oi surfaces which are intended to work relation 'may-be ground with one clamping of the work,` thereby ground coo rating surfaces. v

To those illed. in theartinany modifications of, and widely differing embodiments and applications of my invention will suggest themselves, without departing f romthe spirit and scope thereof; .Myjdisclosures and the descriptions herein are vpurely illustrative in cooperating insuring uniformly andare not intended to be in any sense limiting.

. WhatIclaim is:

1. ln radius grinding mechanism ada ted to cooperate with a rotatable grinding w eel, in combination, a base, a carriage mounted for longitudinal movementl on said base, a work support pivotally mounted on saidcarriage so that the pivotal axis of said work support Will remain in fixed lateral position relative to said work support and will travel in a true plane which includes the axis of said grinding wheel, means to cause longitudinal travel of the carriage on said base, and means for moving said Work support about the pivotal axis thereof during the longitudinal movement of the carriage.

2. In radius grinding mechanism adapted to cooperate with a rotatable grinding wheel, in combination, a base, a carriage mounted for longitudinal movement on said base, a work support provided with a lever arm of redetermined length, said work support belng pivotally mounted on said carriageL so that the pivotal axis of said work support will travel in a plane which includes the axis of said grinding wheel and in which plane at one point of said travel said pivotal axis is in longitudinal alignment with the grinding wheel axis, means to cause longitudinal travel of the carriage on said base, and means engaging said lever arm to move the outereiective end thereof, said means moving simultaneously with the longitudinal travel of said carriage only in directions perpendicular to the plane of travel of said Work support at such a rate that the travel of said effective end of said lever ai'm at successive positions thereof, measured in said perpendicular directions, will be proportional to the sine of half the angle included between the theoretical center of the arc being ground and the pivotal axis of the Work support at corresponding successive positions thereof.

3. A radius grinding unit adapted to be disposed on the table of a grinding machine comprising, in combination, a base ada ted to be disposed on the table of said grin 'ng machine, a carriage mounted for movement longitudinally of said base and transversely of the axis of the grinding wheel of said machine, a work support pivotally mounted on said carriage so that the pivotal axis of said work support will remain in fixed lateral position relative to said work support andV will travel in a true plane which includes the axis of said grinding wheel, means carried by the base to cause longitudinal travel of the carriage on said base, means carried b v the base for moving said work support about the pivotal axis thereof simultaneously with the longitudinal movement of the carriage, and

means to reverse the direction lof longitudinal travel of said carriage and of the pivotal movement of said work support.

4. A radius grinding unit adapted to be disposed on the table of a grinding machine comprising, in combination, a base adapted to be disposed on thc table of said grinding machine, a carriage mounted or movement longitudinally of said base and transversely of the axis or the grinding wheel of said ina-` cliine, a work support pvotally mounted on said carriage so that the pivotal axis of said work support Will remain in iixedlateral positionrelative to said work support and will travel in a plane which includes the 'axis 0f sai-d grinding wheel, means for adjusting said work support vertically to a. relatively great degree with respect to the grinding wheel and to said axis, a motor mounted on said base, means driven by said motor to cause longitudinaltravel of the carriage on said base at one of-a plurality of speeds, means driven by said motor for moving said work support about the pivotal axis thereof simultaneously with the longitudinal movement of thelcarriage, and means to automatically and simultaneously reverse the direction of lon tudinal travel of said carriage and of 51e pivotal movement of said work support.

5. A radius grinding unit adapted to be mounted on a inding machine table in cooperative relation to a grinding wheel and grinding wheel spindle, and means to cause reciprocative movement between said grinding wheel and table longitudinally of said grinding wheel spindle comprising, in combination, a base adapted to be disposed on the table of said grinding machine, a carriage mounted for movement longitudinally of said base and transversely ofthe axis of the grinding wheel of said machine, a work support pivotally mounted on said carriage so that the pivotal axis of said work support will remain in fixed lateral position relative to said work support and will travel in a plane which includes the axis of said grinding wheel, means carried by the base to cause longitudi nal travel of the carriage on said base, means carried by the base for moving said work support about the pivotal axis thereof simultaneously with the longitudinal movement of the carriage, means to automatically and simultaneousl reverse the direction of lon tudinal trave of Said carriage and of t e pivotal movement of. said work support, and means on the grinding machine to automatically reverse the directionv of said reci rocative movement between the grinding w eel and table.

6. In radius grinding mechanism ada ted to coo crate with a rotatable grinding wlieelI in com ination, a base, a carriage mounted for longitudinal movement on said base, a Work support pivotally mounted on said carriage so that the pivotal axis of said Work support will trave in a plane which includes the axis of saidvgrinding wheelpmeans for moving said work support about the pivotal axis loll l, io

r to cooperate with a rotatable grinding w eel,`

Pil'

insana l lnally moving member ixedly disposable with respect to said leverarm and freely slidable vin a direction perpendicular to the direction of movement of said longitudinally moving member, whereby said work support may be' Jpivotally moved through a lever arm of oo nstant length but at a distance of varying Vlength perpendicular to the direction of e movement of said member.

7 In radius grinding Amechanism ada ted in combination, a bm, a carriage mounted on said base for movement longitudinally of said base 'and transversely of the axis of said grindin Wheel, a work support pivotally mounte on said carriage so that the pivotal axis of said'work support will travel in a planewhich includes-the`axisof said ding wheel, means for movin said wor support about its pivotal axis uring the longitudinal movement of the carriage including a graduated lever arm, pivoted at the pivotal -base, a carriage mounted on sai t, movement lon 'tudinally transversely o axis of said workv support, amember movable only in a plane perpendicular to the plane of travel of thefpivotal axis of said work support, means to actuate said member during the longitudinal movement ofsaidl carriage, and means to transmit said movement from said member'to said lever arm comprising a stud adjustable to provide a lever arm of predetermined length, said stud being slidable with respect to said member in a direction `perpendicular to the direction of movement of said member. ,f l

8. In radius grindin mechanism, in combination with a rot-ata le grindin wheel, a base for the axis of said grinding wheel, a work support pivotally mountedon said carriage so lthat the ivotal axisof said. work support will travel in a plane which 1ncludes the axis of said grinding wheel, means forl movin said work support about its pivotal axis ring the longitudinal movement of the carriage including a graduated lever arm pivoted at the pivotal axis of said work support, a slotted member movable only in a V,plane perpendicularto the plane of travel of the pivotal axisof said .work support, meansA to movesaid slotted member by means carried Y bythe lcarriage during the longitudinal move;

ment ofisaid carriage, and means to transmit y said movement `from .said member to said le,-V ver comprising a stud adjustable to pro ofsaid base and plane which includes the axis of said vide a lever arm of predetermined length,

said stud being slidable with respect to said member in adirection perpendicular to the direction of movement of said member.

9. In radius grinding mechanism adapted /tocooperate with a rotatable grinding wheel,

ln'combination, a base adapted to be positioned on a. support, a carriage mounted for movement on said base, longitudinally of said base and transverselyA of the. axis of said grinding wheel, a work support pivotally mounted on said carriage so that the pivotal axis of saidl work support Willremain inixed lateral position relative to saidwork support and will travel in a plane which includes the axis of said grinding wheel, whereby the workl l may be moved transversely and pivotally with respect to-said grinding wheel, and

means carried 'by said carriage Wherebyisaid work support may be moved to a rela-tivelygreat extent in a pla-ne perpendicular to-,the axis of said grinding wheel and to -the pivotal axis of the work support, whereby a plurality of surfaces of desired radius may be readily ground with the same mount-ing of the work.

. .10. In-radius grinding mechanism ada ted to cooperate with a rotatable grindin w in combination, a base adapted -to e tioned von a support,'a carriagemountedxir movement on said base, longitudinally of said base and transversely of the axis of. 'said grindin wheel, a work support 'pivotally mounte on said carrie-ganso that the pivotal axis of said work support will travel in a plane which includes the axis of said grindin eel,

wheel, means for pivotally moving said wor Y support including a lever arm pivoted at the pivotal axis' of said work support, lineark uniform graduations of'large scale on said lever arm extending throughout 'the range of radii of arcs to be ground, and means for ac3 los tuating said lever including a pivot studi I' indicating the desired radius, the scale of said adapted to be set at the pointof graduation. l

graduations being suilicieutly large so that the stud may be readily and accurately'set at the ldesired radius.

11. `In radius grinding mechanismada ted to cooperate with a rotatable grindingew ee'l, in combination, a base adapted to tioned on a support, a carriage' molin for movement -on said base, longitudinally' of said base and-transversely of wheel a work support pivotally on said carriage' so that the pivotal axis of said work'support will travelV da m ing wheel, meansfor moving'said wor support about its pivotal axisincluding a lever le axis of said arm pivoted at the pivotal axis of said work support linear uniform graduations of large -egcale onsaid lever arm extending throughout the range of radii of arcs'to be ground, means 130 for actuating said lever including a pivot stud with graduations vin terms of grinding site the radius of the arc to be groun ing wheel.

adapted to be set at the oint of graduation indicating the desired ra `us, and means for compensating for the diameter of the grinding wheel, whether grinding internal, or external arcs, said compensating meanslincluding a portion cooperatively associated and movable with said. pivot stud and provided wheel dimensions, whereb said stud may be set with respect to the ever withthe dimension of the desired grinding wheel directl1 oppothereby eliininatin the necessity for computing an allowance L or the dimension of the grind- 12.' The method of grindin trueciracular arcuate surfaces of long radii, which comprises, disposing the work to be ground adjacent a grinding wheel on a pivotally mounted work support, rotating said grinding wheel, causing said work support to travel bodily transversely of the axis of said 'nding wheel so that the pivotal axis o said work support will remain in fixed lateral position relative to said work support and will travel in a plane which includes the axis of said grinding wheel,` and moving. said work support about the pivotal axis thereof simultaneously with the transverse movement of said work support, whereby to cause the work mounted on said work support to present to the grinding wheel a true circular arcuate surface to be ground.`

13. The method of grindi true circular arcuate surfaces of long radii, which comprises, disposing the work to.be ground ad jacent a grinding wheel on a pivotally mount-v ed' work support provided with a lever arm of predetermined length, rotating said grinding wheel, causing said work su port travel bodily transversely of the axis of said grinding wheel so that the pivotal axis of `said work support will travel a pinne which includes the axis of said grinding wheel, and

in which plane, at one point of said travel, said pivotal axis is in longitudinal alignment with the grinding wheel axis, movin said work support about the pivotal axis tiiereof simultaneously with the transverse movement of said work support by moving the outer end of said lever ami by means moving only in directions perpendicular to said plane of travel of the work support at such a rate that the travel of the end of said lever arm at successive positions thereof, measured in said perpendicular directions, will be proportional to the sine of half the angle included between the theoretical center of the arc being ground and the pivotal axis of the work support at corresponding successive positions thereof.

' 14. The. method of grinding true circular arcuate surfaces of long radii, which comprises, disposing the work to be ground adjacent a grinding wheel on a pivotally mounted work support provided with a lever arm of predeterpnned len'gth, rotating said grinding wheel, causing ,said work support to travel bodily transversely of the axis of said grinding wheel` so that the pivotal axis of said work support will travel in a true plane which includes the axis of said grinding wheel, pivotally moving said work support about the pivotal axis thereof simultaneously with the transverse movement of said work support b applying force to the effective outer end o said lever arm, only in directions perpendicular to the lever arm at one sition thereof, whereby the distance ara el to said lever arm at said position om the pivotal axis of said lever to the point of application of said force is continuously varied and whereby to cause the work mounted on the work support to present to the grinding wheel a true circular arcuate surface to be ground.

In testimony whereof I aiiix my si ature. WILLIAM C. PAL IER. 

